/*
 *  Public Key abstraction layer: wrapper functions
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 *
 *  This file is provided under the Apache License 2.0, or the
 *  GNU General Public License v2.0 or later.
 *
 *  **********
 *  Apache License 2.0:
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  **********
 *
 *  **********
 *  GNU General Public License v2.0 or later:
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  **********
 */

#if !defined(MBEDTLS_CONFIG_FILE)
#include "nettls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#if defined(MBEDTLS_PK_C)
#include "nettls/pk_internal.h"

/* Even if RSA not activated, for the sake of RSA-alt */
#include "nettls/rsa.h"

#include <string.h>

#if defined(MBEDTLS_ECP_C)
#include "nettls/ecp.h"
#endif

#if defined(MBEDTLS_ECDSA_C)
#include "nettls/ecdsa.h"
#endif

#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
#include "nettls/platform_util.h"
#endif

#if defined(MBEDTLS_PLATFORM_C)
#include "nettls/platform.h"
#else
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free   free
#endif

#include <limits.h>
#include <stdint.h>

#if defined(MBEDTLS_RSA_C)
static int rsa_can_do(mbedtls_pk_type_t type)
{
    return (type == MBEDTLS_PK_RSA || type == MBEDTLS_PK_RSASSA_PSS);
}

static size_t rsa_get_bitlen(const void* ctx)
{
    const mbedtls_rsa_context* rsa = (const mbedtls_rsa_context*)ctx;
    return (8 * mbedtls_rsa_get_len(rsa));
}

static int rsa_verify_wrap(void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len)
{
    int ret;
    mbedtls_rsa_context* rsa = (mbedtls_rsa_context*)ctx;
    size_t rsa_len = mbedtls_rsa_get_len(rsa);

#if SIZE_MAX > UINT_MAX
    if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);
#endif /* SIZE_MAX > UINT_MAX */

    if (sig_len < rsa_len)
        return (MBEDTLS_ERR_RSA_VERIFY_FAILED);

    if ((ret = mbedtls_rsa_pkcs1_verify(rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC, md_alg, (unsigned int)hash_len, hash, sig)) != 0)
        return (ret);

    /* The buffer contains a valid signature followed by extra data.
     * We have a special error code for that so that so that callers can
     * use mbedtls_pk_verify() to check "Does the buffer start with a
     * valid signature?" and not just "Does the buffer contain a valid
     * signature?". */
    if (sig_len > rsa_len)
        return (MBEDTLS_ERR_PK_SIG_LEN_MISMATCH);

    return (0);
}

static int rsa_sign_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    mbedtls_rsa_context* rsa = (mbedtls_rsa_context*)ctx;

#if SIZE_MAX > UINT_MAX
    if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);
#endif /* SIZE_MAX > UINT_MAX */

    *sig_len = mbedtls_rsa_get_len(rsa);

    return (mbedtls_rsa_pkcs1_sign(rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE, md_alg, (unsigned int)hash_len, hash, sig));
}

static int rsa_decrypt_wrap(
    void* ctx,
    const unsigned char* input,
    size_t ilen,
    unsigned char* output,
    size_t* olen,
    size_t osize,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    mbedtls_rsa_context* rsa = (mbedtls_rsa_context*)ctx;

    if (ilen != mbedtls_rsa_get_len(rsa))
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    return (mbedtls_rsa_pkcs1_decrypt(rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE, olen, input, output, osize));
}

static int rsa_encrypt_wrap(
    void* ctx,
    const unsigned char* input,
    size_t ilen,
    unsigned char* output,
    size_t* olen,
    size_t osize,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    mbedtls_rsa_context* rsa = (mbedtls_rsa_context*)ctx;
    *olen = mbedtls_rsa_get_len(rsa);

    if (*olen > osize)
        return (MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE);

    return (mbedtls_rsa_pkcs1_encrypt(rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC, ilen, input, output));
}

static int rsa_check_pair_wrap(const void* pub, const void* prv)
{
    return (mbedtls_rsa_check_pub_priv((const mbedtls_rsa_context*)pub, (const mbedtls_rsa_context*)prv));
}

static void* rsa_alloc_wrap(void)
{
    void* ctx = mbedtls_calloc(1, sizeof(mbedtls_rsa_context));

    if (ctx != NULL)
        mbedtls_rsa_init((mbedtls_rsa_context*)ctx, 0, 0);

    return (ctx);
}

static void rsa_free_wrap(void* ctx)
{
    mbedtls_rsa_free((mbedtls_rsa_context*)ctx);
    mbedtls_free(ctx);
}

static void rsa_debug(const void* ctx, mbedtls_pk_debug_item* items)
{
    items->type = MBEDTLS_PK_DEBUG_MPI;
    items->name = "rsa.N";
    items->value = &(((mbedtls_rsa_context*)ctx)->N);

    items++;

    items->type = MBEDTLS_PK_DEBUG_MPI;
    items->name = "rsa.E";
    items->value = &(((mbedtls_rsa_context*)ctx)->E);
}

const mbedtls_pk_info_t mbedtls_rsa_info = {
    MBEDTLS_PK_RSA,
    "RSA",
    rsa_get_bitlen,
    rsa_can_do,
    rsa_verify_wrap,
    rsa_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    rsa_decrypt_wrap,
    rsa_encrypt_wrap,
    rsa_check_pair_wrap,
    rsa_alloc_wrap,
    rsa_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    rsa_debug,
};
#endif /* MBEDTLS_RSA_C */

#if defined(MBEDTLS_ECP_C)
/*
 * Generic EC key
 */
static int eckey_can_do(mbedtls_pk_type_t type)
{
    return (type == MBEDTLS_PK_ECKEY || type == MBEDTLS_PK_ECKEY_DH || type == MBEDTLS_PK_ECDSA);
}

static size_t eckey_get_bitlen(const void* ctx)
{
    return (((mbedtls_ecp_keypair*)ctx)->grp.pbits);
}

#if defined(MBEDTLS_ECDSA_C)
/* Forward declarations */
static int
    ecdsa_verify_wrap(void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len);

static int ecdsa_sign_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng);

static int
    eckey_verify_wrap(void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len)
{
    int ret;
    mbedtls_ecdsa_context ecdsa;

    mbedtls_ecdsa_init(&ecdsa);

    if ((ret = mbedtls_ecdsa_from_keypair(&ecdsa, ctx)) == 0)
        ret = ecdsa_verify_wrap(&ecdsa, md_alg, hash, hash_len, sig, sig_len);

    mbedtls_ecdsa_free(&ecdsa);

    return (ret);
}

static int eckey_sign_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    int ret;
    mbedtls_ecdsa_context ecdsa;

    mbedtls_ecdsa_init(&ecdsa);

    if ((ret = mbedtls_ecdsa_from_keypair(&ecdsa, ctx)) == 0)
        ret = ecdsa_sign_wrap(&ecdsa, md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng);

    mbedtls_ecdsa_free(&ecdsa);

    return (ret);
}

#if defined(MBEDTLS_ECP_RESTARTABLE)
/* Forward declarations */
static int ecdsa_verify_rs_wrap(
    void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len, void* rs_ctx);

static int ecdsa_sign_rs_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng,
    void* rs_ctx);

/*
 * Restart context for ECDSA operations with ECKEY context
 *
 * We need to store an actual ECDSA context, as we need to pass the same to
 * the underlying ecdsa function, so we can't create it on the fly every time.
 */
typedef struct {
    mbedtls_ecdsa_restart_ctx ecdsa_rs;
    mbedtls_ecdsa_context ecdsa_ctx;
} eckey_restart_ctx;

static void* eckey_rs_alloc(void)
{
    eckey_restart_ctx* rs_ctx;

    void* ctx = mbedtls_calloc(1, sizeof(eckey_restart_ctx));

    if (ctx != NULL) {
        rs_ctx = ctx;
        mbedtls_ecdsa_restart_init(&rs_ctx->ecdsa_rs);
        mbedtls_ecdsa_init(&rs_ctx->ecdsa_ctx);
    }

    return (ctx);
}

static void eckey_rs_free(void* ctx)
{
    eckey_restart_ctx* rs_ctx;

    if (ctx == NULL)
        return;

    rs_ctx = ctx;
    mbedtls_ecdsa_restart_free(&rs_ctx->ecdsa_rs);
    mbedtls_ecdsa_free(&rs_ctx->ecdsa_ctx);

    mbedtls_free(ctx);
}

static int eckey_verify_rs_wrap(
    void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len, void* rs_ctx)
{
    int ret;
    eckey_restart_ctx* rs = rs_ctx;

    /* Should never happen */
    if (rs == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    /* set up our own sub-context if needed (that is, on first run) */
    if (rs->ecdsa_ctx.grp.pbits == 0)
        MBEDTLS_MPI_CHK(mbedtls_ecdsa_from_keypair(&rs->ecdsa_ctx, ctx));

    MBEDTLS_MPI_CHK(ecdsa_verify_rs_wrap(&rs->ecdsa_ctx, md_alg, hash, hash_len, sig, sig_len, &rs->ecdsa_rs));

cleanup:
    return (ret);
}

static int eckey_sign_rs_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng,
    void* rs_ctx)
{
    int ret;
    eckey_restart_ctx* rs = rs_ctx;

    /* Should never happen */
    if (rs == NULL)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);

    /* set up our own sub-context if needed (that is, on first run) */
    if (rs->ecdsa_ctx.grp.pbits == 0)
        MBEDTLS_MPI_CHK(mbedtls_ecdsa_from_keypair(&rs->ecdsa_ctx, ctx));

    MBEDTLS_MPI_CHK(ecdsa_sign_rs_wrap(&rs->ecdsa_ctx, md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng, &rs->ecdsa_rs));

cleanup:
    return (ret);
}
#endif /* MBEDTLS_ECP_RESTARTABLE */
#endif /* MBEDTLS_ECDSA_C */

static int eckey_check_pair(const void* pub, const void* prv)
{
    return (mbedtls_ecp_check_pub_priv((const mbedtls_ecp_keypair*)pub, (const mbedtls_ecp_keypair*)prv));
}

static void* eckey_alloc_wrap(void)
{
    void* ctx = mbedtls_calloc(1, sizeof(mbedtls_ecp_keypair));

    if (ctx != NULL)
        mbedtls_ecp_keypair_init(ctx);

    return (ctx);
}

static void eckey_free_wrap(void* ctx)
{
    mbedtls_ecp_keypair_free((mbedtls_ecp_keypair*)ctx);
    mbedtls_free(ctx);
}

static void eckey_debug(const void* ctx, mbedtls_pk_debug_item* items)
{
    items->type = MBEDTLS_PK_DEBUG_ECP;
    items->name = "eckey.Q";
    items->value = &(((mbedtls_ecp_keypair*)ctx)->Q);
}

const mbedtls_pk_info_t mbedtls_eckey_info = {
    MBEDTLS_PK_ECKEY,
    "EC",
    eckey_get_bitlen,
    eckey_can_do,
#if defined(MBEDTLS_ECDSA_C)
    eckey_verify_wrap,
    eckey_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
    eckey_verify_rs_wrap,
    eckey_sign_rs_wrap,
#endif
#else  /* MBEDTLS_ECDSA_C */
    NULL,
    NULL,
#endif /* MBEDTLS_ECDSA_C */
    NULL,
    NULL,
    eckey_check_pair,
    eckey_alloc_wrap,
    eckey_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    eckey_rs_alloc,
    eckey_rs_free,
#endif
    eckey_debug,
};

/*
 * EC key restricted to ECDH
 */
static int eckeydh_can_do(mbedtls_pk_type_t type)
{
    return (type == MBEDTLS_PK_ECKEY || type == MBEDTLS_PK_ECKEY_DH);
}

const mbedtls_pk_info_t mbedtls_eckeydh_info = {
    MBEDTLS_PK_ECKEY_DH,
    "EC_DH",
    eckey_get_bitlen, /* Same underlying key structure */
    eckeydh_can_do,
    NULL,
    NULL,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    NULL,
    NULL,
    eckey_check_pair,
    eckey_alloc_wrap, /* Same underlying key structure */
    eckey_free_wrap,  /* Same underlying key structure */
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    eckey_debug, /* Same underlying key structure */
};
#endif /* MBEDTLS_ECP_C */

#if defined(MBEDTLS_ECDSA_C)
static int ecdsa_can_do(mbedtls_pk_type_t type)
{
    return (type == MBEDTLS_PK_ECDSA);
}

static int
    ecdsa_verify_wrap(void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len)
{
    int ret;
    ((void)md_alg);

    ret = mbedtls_ecdsa_read_signature((mbedtls_ecdsa_context*)ctx, hash, hash_len, sig, sig_len);

    if (ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH)
        return (MBEDTLS_ERR_PK_SIG_LEN_MISMATCH);

    return (ret);
}

static int ecdsa_sign_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    return (mbedtls_ecdsa_write_signature((mbedtls_ecdsa_context*)ctx, md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng));
}

#if defined(MBEDTLS_ECP_RESTARTABLE)
static int ecdsa_verify_rs_wrap(
    void* ctx, mbedtls_md_type_t md_alg, const unsigned char* hash, size_t hash_len, const unsigned char* sig, size_t sig_len, void* rs_ctx)
{
    int ret;
    ((void)md_alg);

    ret = mbedtls_ecdsa_read_signature_restartable((mbedtls_ecdsa_context*)ctx, hash, hash_len, sig, sig_len, (mbedtls_ecdsa_restart_ctx*)rs_ctx);

    if (ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH)
        return (MBEDTLS_ERR_PK_SIG_LEN_MISMATCH);

    return (ret);
}

static int ecdsa_sign_rs_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng,
    void* rs_ctx)
{
    return (mbedtls_ecdsa_write_signature_restartable(
        (mbedtls_ecdsa_context*)ctx, md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng, (mbedtls_ecdsa_restart_ctx*)rs_ctx));
}
#endif /* MBEDTLS_ECP_RESTARTABLE */

static void* ecdsa_alloc_wrap(void)
{
    void* ctx = mbedtls_calloc(1, sizeof(mbedtls_ecdsa_context));

    if (ctx != NULL)
        mbedtls_ecdsa_init((mbedtls_ecdsa_context*)ctx);

    return (ctx);
}

static void ecdsa_free_wrap(void* ctx)
{
    mbedtls_ecdsa_free((mbedtls_ecdsa_context*)ctx);
    mbedtls_free(ctx);
}

#if defined(MBEDTLS_ECP_RESTARTABLE)
static void* ecdsa_rs_alloc(void)
{
    void* ctx = mbedtls_calloc(1, sizeof(mbedtls_ecdsa_restart_ctx));

    if (ctx != NULL)
        mbedtls_ecdsa_restart_init(ctx);

    return (ctx);
}

static void ecdsa_rs_free(void* ctx)
{
    mbedtls_ecdsa_restart_free(ctx);
    mbedtls_free(ctx);
}
#endif /* MBEDTLS_ECP_RESTARTABLE */

const mbedtls_pk_info_t mbedtls_ecdsa_info = {
    MBEDTLS_PK_ECDSA,
    "ECDSA",
    eckey_get_bitlen, /* Compatible key structures */
    ecdsa_can_do,
    ecdsa_verify_wrap,
    ecdsa_sign_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
    ecdsa_verify_rs_wrap,
    ecdsa_sign_rs_wrap,
#endif
    NULL,
    NULL,
    eckey_check_pair, /* Compatible key structures */
    ecdsa_alloc_wrap,
    ecdsa_free_wrap,
#if defined(MBEDTLS_ECP_RESTARTABLE)
    ecdsa_rs_alloc,
    ecdsa_rs_free,
#endif
    eckey_debug, /* Compatible key structures */
};
#endif /* MBEDTLS_ECDSA_C */

#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/*
 * Support for alternative RSA-private implementations
 */

static int rsa_alt_can_do(mbedtls_pk_type_t type)
{
    return (type == MBEDTLS_PK_RSA);
}

static size_t rsa_alt_get_bitlen(const void* ctx)
{
    const mbedtls_rsa_alt_context* rsa_alt = (const mbedtls_rsa_alt_context*)ctx;

    return (8 * rsa_alt->key_len_func(rsa_alt->key));
}

static int rsa_alt_sign_wrap(
    void* ctx,
    mbedtls_md_type_t md_alg,
    const unsigned char* hash,
    size_t hash_len,
    unsigned char* sig,
    size_t* sig_len,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    mbedtls_rsa_alt_context* rsa_alt = (mbedtls_rsa_alt_context*)ctx;

#if SIZE_MAX > UINT_MAX
    if (UINT_MAX < hash_len)
        return (MBEDTLS_ERR_PK_BAD_INPUT_DATA);
#endif /* SIZE_MAX > UINT_MAX */

    *sig_len = rsa_alt->key_len_func(rsa_alt->key);

    return (rsa_alt->sign_func(rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE, md_alg, (unsigned int)hash_len, hash, sig));
}

static int rsa_alt_decrypt_wrap(
    void* ctx,
    const unsigned char* input,
    size_t ilen,
    unsigned char* output,
    size_t* olen,
    size_t osize,
    int (*f_rng)(void*, unsigned char*, size_t),
    void* p_rng)
{
    mbedtls_rsa_alt_context* rsa_alt = (mbedtls_rsa_alt_context*)ctx;

    ((void)f_rng);
    ((void)p_rng);

    if (ilen != rsa_alt->key_len_func(rsa_alt->key))
        return (MBEDTLS_ERR_RSA_BAD_INPUT_DATA);

    return (rsa_alt->decrypt_func(rsa_alt->key, MBEDTLS_RSA_PRIVATE, olen, input, output, osize));
}

#if defined(MBEDTLS_RSA_C)
static int rsa_alt_check_pair(const void* pub, const void* prv)
{
    unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
    unsigned char hash[32];
    size_t sig_len = 0;
    int ret;

    if (rsa_alt_get_bitlen(prv) != rsa_get_bitlen(pub))
        return (MBEDTLS_ERR_RSA_KEY_CHECK_FAILED);

    memset(hash, 0x2a, sizeof(hash));

    if ((ret = rsa_alt_sign_wrap((void*)prv, MBEDTLS_MD_NONE, hash, sizeof(hash), sig, &sig_len, NULL, NULL)) != 0) {
        return (ret);
    }

    if (rsa_verify_wrap((void*)pub, MBEDTLS_MD_NONE, hash, sizeof(hash), sig, sig_len) != 0) {
        return (MBEDTLS_ERR_RSA_KEY_CHECK_FAILED);
    }

    return (0);
}
#endif /* MBEDTLS_RSA_C */

static void* rsa_alt_alloc_wrap(void)
{
    void* ctx = mbedtls_calloc(1, sizeof(mbedtls_rsa_alt_context));

    if (ctx != NULL)
        memset(ctx, 0, sizeof(mbedtls_rsa_alt_context));

    return (ctx);
}

static void rsa_alt_free_wrap(void* ctx)
{
    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_rsa_alt_context));
    mbedtls_free(ctx);
}

const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
    MBEDTLS_PK_RSA_ALT,
    "RSA-alt",
    rsa_alt_get_bitlen,
    rsa_alt_can_do,
    NULL,
    rsa_alt_sign_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    rsa_alt_decrypt_wrap,
    NULL,
#if defined(MBEDTLS_RSA_C)
    rsa_alt_check_pair,
#else
    NULL,
#endif
    rsa_alt_alloc_wrap,
    rsa_alt_free_wrap,
#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
    NULL,
    NULL,
#endif
    NULL,
};

#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */

#endif /* MBEDTLS_PK_C */
